Methods, Systems and Apparatus for Relieving Pressure in an Organ

Abstract

Methods, systems and apparatus for relieving pressure in an organ such as, but not limited to, the eye are disclosed. The method includes implanting a bioabsorbable, channel into the selected area of the organ using a delivery apparatus.

1 . An implantable microfistula channel comprising;
 a bioabsorbable channel body defining at least one interior flow path;   said channel body made of a cross-linked gelatin, said body having an expandable outer diameter; and   said at least one interior flow path having a diameter of between approximately 50 and 250 microns.   
   
   
       2 . The channel of  claim 1  wherein said body has an inner diameter that does not decrease when said outer diameter is expanded. 
   
   
       3 . The channel of  claim 2  wherein said outer diameter is between approximately 200-360 microns when expanded. 
   
   
       4 . The channel of  claim 1  wherein said channel implanted in a desired anatomic location is capable of stimulating development of drainage structures in the body of a patient. 
   
   
       5 . The channel of  claim 4  wherein said drainage structures comprise lymphatic vessels. 
   
   
       6 . The channel of  claim 4  wherein said drainage structures comprise veins. 
   
   
       7 . The channel of  claim 1  wherein said body comprises a varying outer diameter, a proximal end and a distal end, wherein said outer diameter is different at said proximal end than at said distal end. 
   
   
       8 . The channel of  claim 7  wherein said body is tapered. 
   
   
       9 . The channel of  claim 1  wherein said body comprises an outer surface including at least one retainer on said surface. 
   
   
       10 . The channel of  claim 9  wherein said retainer comprises a barb. 
   
   
       11 . The channel of  claim 9  wherein said retainer comprises a deployable tab. 
   
   
       12 . The channel of  claim 11  wherein said deployable tab expands in a direction away from said outer surface when said channel is exposed to an aqueous environment. 
   
   
       13 . The channel of  claim 1  wherein said body comprises a pharmaceutical compound incorporated therein. 
   
   
       14 . A method of making an implantable microfistula channel comprising:
 (a) providing a gelatin solution;   (b) providing a generally cylindrical solid support having an outer surface, said support having a diameter of approximately 50-250 microns;   (c) contacting said outer surface of said support with said gelatin for a period of time sufficient to coat said support outer surface;   (d) forming a hollow gelatin channel on said support;   (e) curing said formed channel for a selected period of time;   (f) subjecting said gelatin channel to a cross-linking treatment; and   (g) removing said cross-linked channel from said support.   
   
   
       15 . The method of  claim 14  comprising providing a bath of gelatin solution. 
   
   
       16 . The method of  claim 15  comprising maintaining said bath at a selected temperature. 
   
   
       17 . The method of  claim 16  comprising maintaining said bath at a temperature of approximately 40°-60° C. 
   
   
       18 . The method of  claim 15  wherein said gelatin solution comprises approximately 40%, by weight, of gelatin dissolved in water. 
   
   
       19 . The method of  claim 15  comprising stirring said gelatin solution. 
   
   
       20 . The method of  claim 14  wherein said cylindrical support comprises a stainless steel wire coated with a biocompatible material. 
   
   
       21 . The method of  claim 20  wherein said coating is polytetrafluoroethylene. 
   
   
       22 . The method of  claim 14  comprising contacting said support with said gelatin by dipping said wire into a bath including said gelatin solution. 
   
   
       23 . The method of  claim 20  comprising providing a weight at one end of said wire. 
   
   
       24 . The method of  claim 22  comprising repeating said dipping step. 
   
   
       25 . The method of  claim 22  comprising rotating said wire during said dipping. 
   
   
       26 . The method of  claim 14  wherein said contacting comprises spraying a gelatin solution onto a rotating support. 
   
   
       27 . The method of  claim 14  wherein the gelatin solution has a viscosity of approximately 200-500 cP. 
   
   
       28 . The method of  claim 14  comprising drying said gelatin channel for a period of at least 1 hour prior to cross-linking. 
   
   
       29 . The method of  claim 14  comprising drying said gelatin channel for a period of 10-20 hours. 
   
   
       30 . The method of  claim 29  comprising curing said gelatin channel for at approximately 20°-25° C. at a relative humidity of approximately 30%-40%. 
   
   
       31 . The method of  claim 14  comprising subjecting said gelatin channel to cross-linking by contacting said formed gelatin channel with a cross-linking agent. 
   
   
       32 . The method of  claim 31  wherein said cross-linking agent comprises a solution of glutaraldehyde. 
   
   
       33 . The method of  claim 32  comprising dipping said gelatin channel in a 25% glutaraldehyde solution. 
   
   
       34 . The method of  claim 33  comprising dipping said support with a film of gelatin thereon in a 25% glutaraldehyde solution. 
   
   
       35 . The method of  claim 34  comprising contacting said gelatin channel with said glutaraldehyde for at least 4 hours. 
   
   
       36 . The method of  claim 35  comprising contacting said gelatin channel with said glutaraldehyde solution for a period of approximately 16 hours. 
   
   
       37 . The method of  claim 14  comprising rinsing said gelatin channel with a rinsing solution after said contacting. 
   
   
       38 . The method of  claim 37  comprising drying said gelatin channel after said rinsing. 
   
   
       39 . The method of  claim 38  comprising drying said gelatin channel for a period of approximately 48-96 hours. 
   
   
       40 . The method of  claim 34  wherein said 25% glutaraldehyde solution has a pH of approximately 7.35-7.44 at 4° C. 
   
   
       41 . The method of  claim 14  wherein said cross linking treatment comprises exposing said gelatin channel to radiation. 
   
   
       42 . The method of  claim 41  wherein said radiation is selected from the group consisting of gamma and electron beam radiation. 
   
   
       43 . The method of  claim 29  further comprising treating said channel with a quenching agent. 
   
   
       44 . The method of  claim 29  wherein said cross-linking agent comprises 1-ethyl-3-[e-(dimethylamino)propyl]carbodiimide. 
   
   
       45 . The method of  claim 14  wherein comprising introducing a pharmaceutical agent into at least the outer surface of said gelatin channel. 
   
   
       46 . The method of  claim 45  wherein said pharmaceutical agent is a therapeutic agent. 
   
   
       47 . The method of  claim 37  wherein said rinsing solution comprises water. 
   
   
       48 . An apparatus for implanting a microfistula channel into an organ of a subject comprising:
 a reusable portion comprising a housing having an open distal end, a proximal end and an interior chamber;   an arm sub-assembly within said housing comprising one or more movable arms adapted to receive and engage a disposable needle assembly; one or more drivers coupled to said one or more movable arms of said arm sub-assembly.   
   
   
       49 . The apparatus of  claim 48  comprising a needle assembly secured to said arm sub-assembly. 
   
   
       50 . The apparatus of  claim 49  wherein said needle assembly comprises a hollow needle having a distal portion terminating in a sharpened distal tip, said needle being mounted to a needle hub. 
   
   
       51 . The apparatus of  claim 50  comprising a guidewire disposed within said hollow needle. 
   
   
       52 . The apparatus of  claim 51  wherein said guidewire has a free distal end and a proximal end attached to a guidewire hub. 
   
   
       53 . The apparatus of  claim 49  wherein said needle assembly comprises a generally cylindrical plunger. 
   
   
       54 . The apparatus of  claim 53  comprising a hollow cylindrical plunger placed over said guidewire. 
   
   
       55 . The apparatus of  claim 54  wherein said plunger and said guidewire are coaxial. 
   
   
       56 . The apparatus of  claim 53  wherein said plunger terminates in a distal free end and has a proximal end attached to a plunger hub. 
   
   
       57 . The apparatus of  claim 56  wherein said plunger comprises a hollow tube. 
   
   
       58 . The apparatus of  claim 57  wherein said pushing surface has an outside diameter greater than the remainder of said plunger. 
   
   
       59 . The apparatus of  claim 54  wherein said guidewire hub has an outer diameter smaller than the inner diameter of said plunger hub, such that said guidewire is slidably received by said plunger hub. 
   
   
       60 . The apparatus of  claim 56  further comprising a biocompatible, bioabsorbable microfistula channel slidably placed on said guidewire distal to said plunger free end. 
   
   
       61 . The apparatus of  claim 52  wherein said arm sub-assembly is adapted to receive said guidewire, said plunger and said needle. 
   
   
       62 . The apparatus of  claim 61  wherein said arm-subassembly comprises an arm for receiving said guidewire, an arm for receiving said plunger and an arm for receiving said needle. 
   
   
       63 . The apparatus of  claim 62  wherein said guidewire arm is adapted to receive said guidewire hub. 
   
   
       64 . The apparatus of  claim 63  wherein said guidewire arm comprises a slot for receiving said guidewire hub. 
   
   
       65 . The apparatus of  claim 64  wherein said plunger arm is adapted to receive said plunger hub. 
   
   
       66 . The apparatus of  claim 65  wherein said plunger arm comprises a slot for receiving said plunger hub. 
   
   
       67 . The apparatus of  claim 60  wherein said needle arm is adapted to receive said needle hub. 
   
   
       68 . The apparatus of  claim 66  wherein said needle arm comprises a slot for receiving said needle hub. 
   
   
       69 . The apparatus of  claim 68  wherein said distal portion of said needle is straight. 
   
   
       70 . The apparatus of  claim 69  wherein said distal portion of said needle is bent. 
   
   
       71 . The apparatus of  claim 70  wherein said distal portion of said needle is arcuate. 
   
   
       72 . The apparatus of  claim 71  wherein said needle includes a needle shaft having a longitudinal axis and said tip of said needle is disposed obliquely relative to said longitudinal axis of said shaft. 
   
   
       73 . The apparatus of  claim 70  wherein said distal portion is bent away from said needle shaft by an angle of between 90°-180°. 
   
   
       74 . The apparatus of  claim 73  wherein said hollow needle is made of a rigid metal. 
   
   
       75 . The apparatus of  claim 74  wherein said hollow needle is made of stainless steel. 
   
   
       76 . The apparatus of  claim 75  wherein at least a portion of at least one of said guidewire and said plunger is flexible. 
   
   
       77 . The apparatus of  claim 76  wherein at least a portion of said guidewire comprises a coil or spring. 
   
   
       78 . The apparatus of  claim 76  wherein at least a portion of at least one of said guidewire and plunger is made of a flexible material. 
   
   
       79 . The apparatus of  claim 78  wherein material is selected from the group consisting of polyimide, PEEK, Pebax, Teflon and nitinol. 
   
   
       80 . The apparatus of  claim 48  wherein said one or more drivers comprises a plurality of motors coupled to an arm of said arm sub-assembly. 
   
   
       81 . The apparatus of  claim 48  wherein said arm sub-assembly comprises a guidewire arm, wherein one of said motors is coupled to said guidewire arm. 
   
   
       82 . The apparatus of said  claim 48  wherein said driver comprises a rotatable thumb screw. 
   
   
       83 . The apparatus of claim  448  wherein said driver comprises a plunger activated by a trigger. 
   
   
       84 . A system for implanting a microfistula channel into an organ of a patient comprising:
 a) a reusable portion adapted to receive a needle assembly;   b) a disposable portion comprising a needle assembly, said needle assembly comprising a hollow needle terminating in a sharpened tip, a guidewire disposed within said hollow needle, a plunger disposed within said needle;   c) a microprocessor-based controller including pre-programmed instructions for selective movement of at least said guidewire and said plunger.   
   
   
       85 . The system of  claim 84  further comprising a driver for advancing or retracting at least one of said guidewire and plunger. 
   
   
       86 . The system of  claim 85  wherein said driver comprises a motor. 
   
   
       87 . The system of  claim 86  comprising at least one motor coupled to said power supply and said microprocessor-based controller. 
   
   
       88 . The system of  claim 87  wherein said controller is externally located from said reusable and disposable portions. 
   
   
       89 . The system of  claim 84  wherein said reusable portion comprises an apparatus including a housing having an open distal end, a proximal end and an interior chamber;
 an arm sub-assembly within said housing comprising one or more movable arms adapted to receive and engage a disposable needle assembly; and   one or more drivers coupled to said one or more movable arms of said arm sub-assembly.   
   
   
       90 . The system of  claim 84  wherein said reusable portion comprises an arm subassembly adapted to receive said needle assembly comprising a guidewire, a plunger and a hollow needle. 
   
   
       91 . The apparatus of  claim 89  wherein said arm-subassembly comprises an arm for receiving said guidewire, an arm for receiving said plunger and an arm for receiving said needle. 
   
   
       92 . The system of  claim 85  wherein said controller is coupled to said one or more drivers. 
   
   
       93 . The system of  claim 84  wherein said one or more drivers comprises a plurality of motors coupled to said controller, each of said motors being independently controllable. 
   
   
       94 . The apparatus of  claim 89  further comprising a foot switch for initiating movement of said one or more movable arms. 
   
   
       95 . The system of  claim 93  wherein said plurality of motors are disposed in a parallel configuration. 
   
   
       96 . A method of implanting a microfistula channel into an organ of a subject comprising:
 (a) providing a handheld implantation apparatus including a hollow needle having a pointed distal end, a bioabsorbable microfistula channel within said needle, and a plunger proximally located relative to said microfistula channel;   (b) introducing said pointed distal end into the organ of a subject;   (c) advancing said needle to the desired area of implantation,   (d) actuating said plunger to advance said microfistula channel to said desired area of implantation;   (e) withdrawing said guidewire from said area of implantation; and   (f) removing said needle from said organ.   
   
   
       97 . The method of  claim 96  wherein said organ is an eye, said method comprising introducing said pointed distal end into the anterior chamber of said eye. 
   
   
       98 . The method of  claim 97  comprising advancing said needle through the anterior chamber of the eye. 
   
   
       99 . The method of  claim 98  comprising delivering said microfistula channel to a selected location within the eye whereby one end of said channel resides in the anterior chamber and a second end of said microfistula channel resides in the subconjunctival space. 
   
   
       100 . The method of  claim 96  comprising delivering said channel to a selected location within the eye wherein one end of said tube resides in the anterior chamber and a second end of said channel resides in the suprachoroidal space. 
   
   
       101 . The method of  claim 100  comprising a advancing said microfistula channel at a selected rate. 
   
   
       102 . The method of  claim 95  comprising making an incision in said eye prior to introducing said pointed distal end into said eye. 
   
   
       103 . The method  claim 94  wherein said apparatus includes a guidewire within said hollow needle, said channel being concentrically disposed about said guidewire. 
   
   
       104 . The method of  claim 103  comprising placing said needle, said guidewire and said plunger into a starting position prior to said introducing step. 
   
   
       105 . The method of  claim 104  comprising moving said guidewire and said plunger to a loading position prior to said introducing step. 
   
   
       106 . The method of  claim 105  comprising introducing a needle assembly comprising said needle, said guidewire and said plunger into said apparatus. 
   
   
       107 . The method of  claim 96  comprising providing a needle having an arcuate distal portion and introducing said sharpened tip of said needle into the anterior chamber of the eye. 
   
   
       108 . The method of  claim 107 , comprising rotating said needle and advancing said needle by pulling it to the desired area of implantation. 
   
   
       109 . The method of  claim 106  comprising partially retracting said needle until said microfistula channel and the distal end of said plunger are visible prior to removing said guidewire. 
   
   
       110 . The method of  claim 107  wherein at least said steps (d)-(e) are performed automatically by a pre-programmed controller connected to said apparatus. 
   
   
       111 . The method of  claim 96  comprising forming a natural cell-lined channel in said organ. 
   
   
       112 . The method of  claim 96  comprising forming drainage structures in or around said organ whereby said draining structures provide resistance to flow that maintains an intraocular pressure of between approximately 5-12 mm Hg. 
   
   
       113 . The method of  claim 112  wherein said intraocular pressure is approximately 10-18 mm Hg.